Basic fungal biology presentation lecture.ppt

This is another lecture material on fungi

1. Introductory Mycology BOT 461/561

2. What are fungi?
•Eukaryotic, spore-bearing, heterotrophic
organisms that produce extracellular
enzymes and absorb their nutrition.

3. Body Plan
•unicellular (yeast), filamentous, or both (=dimorphic)
•Hypha (pl. hyphae) is the basic “cellular” unit in
filamentous fungi; they may be septate or coenocytic
(aseptate); collectively a mycelium
•limited tissue differentiation and division of labor
•somatic & reproductive structures
•plectenchyma: all organized fungal tissue, somatic &
reproductive

4. Nuclear Status
•Eukaryotic; uni, bi- or multinucleate
•Haploid, diploid (less frequent)
•Monokaryon
(1 nucleus per hyphal compartment)
•Dikaryon
(2 nuclei per hyphal compartment)

•Homokaryotic
•Heterokaryotic

5. •Mitosis
–intranuclear: nuclear membrane doesn't
breakdown during mitosis
–centric in flagellated forms; typical centrioles
of eukaryotes
–noncentric in nonflagellated forms; possess
spindle pole bodies (SPBs); differ from
centrioles in lacking microtubular component

6. Organelles
•typical eukaryote assemblage of organelles + fungal
specific ones
•mitochondria
•endoplasmic reticulum
•dictyosome cisternae
(=golgi apparatus)
•vacuoles
•microbodies
funx in fatty acid degradation, N metabolism

7. Cell Wall
•well defined
•chitin
1-4 n-acetyal glucosamine
-glucans
polymers of glucose
1-3 glucose
•cellulose in some
1-4 glucose
chitin-glucans
Chitin
Cellulose
 1-3 glucan

8. •fungal specific organelles involved in cell wall growth
Spitzenkorper
associated with growing hyphal tips in septate fungi
chitosome
microvesicles transporting chitin synthases to growing cell wall

9. Nutrition
•Heterotrophic
•Absorptive nutrition
•Secrete extracellular enzymes
•Saprobes: decay dead organic matter
•pathogens: biotroph, necrotroph
•symbionts: parasites - commensals - mutualists

10. Reproduction
•Sexual reproduction: spores meiotically derived nuclei
•Monoecious or dioecious
•Homothallic (selfing)
•Heterothallic (outcrossing)
•Genetic mating system
–MAT loci
–1 to hundreds of “sexes”
•Asexual reproduction
–Spores with mitotically derived nuclei

11. Misc.
•Life cycle: simple to complex; wide variety
•Sporocarps: microscopic or macroscopic,
limited tissue differientiation
•Habitat: ubiquitous
•Studied by mycologists!!!!!!

12. What are fungi?
•Eukaryotic, spore-bearing, heterotrophic
organisms that produce extracelluar
enzymes and absorb their nutrition.

13. Fungi vs. "fungi"
•Based on the phenotypic definition or traits
listed above, fungi do not comprise a single
group of organisms, i.e., more than one
evolutionary origin
•That is to say, not all "fungi" are members
of the Kingdom Fungi

14. FUNGI (e.g., mushrooms, yeasts)
MICROSPORIDIA
METAZOA (Animals)
DICTYOSTELIDAE
MYXOGASTRIDAE
LOBOSA
ANGIOSPERMAE (Green Plants)
CHLOROPHYCEAE
RHODOPHYTA
GLAUCOPHYTA
OOMYCETES
PHAEOPHYCEAE (Brown algae)
CILIOPHORA
APICOMPLEXA
KINETOPLASTIDA
EUGLENOIDEA
ACRASIDAE
VAHLKAMPFIIDAE
PARABASALLA
DIPLOMONADIDA
Slime molds
Phylogeny
Of
Eukaryotes
(some water molds
Sudden Oak Death)

15. Some characters that separate the
Fungi (=the Kingdom Fungi) from "fungi"

Kingdom Fungi Protistan fungi
mitochondria: cristae flattened cristae tubular
motile cells: no motile cells motile cells with anterior
or posterior flagellum or lateral flagella

cell wall
carbohydrate: glucans, chitin glucans, cellulose

lysine biosynthesis:alpha-aminoadepic acid (AAA) diaminopimelic (DAP)
storage compoundglycogen mycolaminarins
sterols ergosterol fucosterol
Phyla: Chytridiomycota Oomycota
Zygomycota Hyphchytriomycota
Basidiomycota Labyrinthulomycota
Ascomycota Myxomycota